The present disclosure is related to resource allocation mechanism of a communication network, and more particularly, to methods and apparatuses for allocating a paging resource to a mobile station having multiple subscriber identities.
Mobile communication applications are already popular in modern daily life. In a mobile communication system, the current resource allocation mechanism of a radio access network, for example, a GSM or UMTS terrestrial radio access network (UTRAN) base station subsystem (BSS), needs to separately arrange different radio resources (such as time slots, paging blocks, or radio frames) for paging multiple subscriber identities.
Please refer to FIG. 1. FIG. 1 is a diagram illustrating paging resource allocation for a mobile station having multiple subscriber identities. In this example, the mobile station has a first subscriber identity IMSI_1 and a second subscriber identity IMSI_2. A mobile station only needs to listen to paging information on every Nth block of the paging channel (PCH). The number N is the block index, and is determined by multiplying the number of paging blocks per 51-frame multiframe of the common control channel (CCCH) with the parameter BS_PA_MFRMS designating the number of multiframes between paging numbers of the same paging group. A simple algorithm is used which allows each mobile station to calculate its respective paging group from its IMSI and parameters BS_PA_MFRMS, N, and BS_CC_CHANS, where BS_CC_CHANS determines the number of physical channels which support a CCCH. FIG. 1 illustrates a PCH comprising 12 paging blocks (block index P1-P12). For example, when there is a paging message targeting the first subscriber identity IMSI_1, the network sends the paging message at paging block P7. If there is a paging message targeting the second subscriber identity IMSI_2, the network sends the paging message at paging block P3. In other words, the mobile station, having two subscriber identities IMSI_1 and IMSI_2, must monitor paging messages at both paging blocks P3 and P7 to avoid missing any paging message sent by the network.
As can be seen from FIG. 1, although the first and second subscriber identities IMSI_1 and IMSI_2 are belong to the same mobile station, the conventional resource allocation mechanism still arranges paging resource independently for the subscriber identities (e.g. paging block P7 for IMSI_1 and paging block P3 for IMSI_2). The paging resource of the network is repeatedly occupied by a single mobile station. Furthermore, the mobile station monitors paging messages at two paging blocks, P3 and P7, which results in higher power consumption and shortens the standby time. This is considered uneconomic for both the network operator and the subscriber with mobile station having multiple subscriber identities.